Shows a panoramic view of the Hoover Dam site in Black Canyon. There are trucks and buildings visible on the floor of the canyon. One of the portals to the diversion tunnels is visible. The concrete pouring...

View of construction of the foundations of the Arizona power house in the Colorado River bed in Black Canyon. Concrete pouring forms stand in the river bed and other construction equipment can be seen. Construction workers can be seen at...

View of construction on the foundations of the Arizona power house in the Colorado River bed in Black Canyon. Concrete pouring forms stand in the river bed below the partially finished face of Hoover Dam, and other construction equipment can...

This aerial photo shows various parts of the dam under construction. Cableways, an overhead tram, various buildings and structures, railroad tracks, trestles, and concrete forms are visible. Also shows the Arizona spillway, Arizona intake towers, the Himix plant...

View of the Hoover Dam construction site in Black Canyon from downstream. Framework and concrete pouring forms are visible on the Nevada power house on the left, the Arizona power house on the right and the central portion of the...

This postcard shows the construction of Hoover Dam in four different stages. All views were taken from the same point looking upstream. The first image shows Black Canyon and the Colorado River at the very beginning of construction...

Shows a general view of dam construction. Cables, buildings, and roads are visible. Concrete pouring forms can be seen at the bottom of the canyon. A portion of the Colorado River is also visible. The...

Shows the concrete pouring forms for the base of the dam. The upper cofferdam is in the background. Cableways, buildings, construction workers and trucks are visible. A railroad track runs along the side of the wall of Black Canyon.

Handwritten inscription on back of photo: "Downstream face of Boulder Dam as seen from low level catwalk. Top forms at elevation 710." Shows the concrete forms for the face of the dam. Buildings and structures can be...

Panoramic view of Black Canyon and Hoover Dam under construction. Two of the portals to the diversion tunnels are visible. The face of the dam is nearing completion and the concrete pouring forms can be seen. Part...

Aerial view of Hoover Dam, Black Canyon, and the Colordo River during the construction of the dam. Two portals of the diversion tunnels are visible. There are trucks and buildings on the cofferdam. The face of the...

Upstream view of the dam showing the downstream face with multiple catwalks across it. Foreground shows the lower cofferdam with the power houses under construction and a headquarters building. To the right are unfinished Arizona intake towers and...